A light emitting device, a light emitting device package, and a lighting system are provided. The light emitting device includes a first conductive type semiconductor layer, a second conductive type semiconductor layer, and an active layer between the first and second conductive type semiconductor layers. The active layer includes a first active layer adjacent to the second conductive type semiconductor layer, a second active layer adjacent to the first conductive type semiconductor layer, and a gate quantum barrier between the first and second active layers.